1. Field of the Invention
The present invention is related to a vibrating gyroscope and, more particularly, to the type of vibrating gyroscope that can be applied for a navigation system providing an appropriate guidance of a vehicle by detecting the position of a moving body by sensing its rotational angular velocity, or to the type of vibrating gyroscope that can be applied for a damping system such as preventing device for preventing shaking of hands that suppresses vibration by detecting an external vibration.
2. Description of the Prior Art
FIG. 7 is an exploded perspective view showing an example of a conventional vibrating gyroscope. The vibrating gyroscope 30 includes a regular triangular prism-shaped vibrating body 31. The vibrating gyroscope 30 is made of a constant-elastic metal material such as elinver. On three side faces of the vibrating body 31, piezoelectric elements 32a, 32b, 32c are secured respectively by suitable means such as an adhesive. The piezoelectric elements 32a, 32b, 32c are made of, for example, by forming electrodes on both surfaces of a piezoelectric ceramics.
An oscillation circuit (not shown) is connected between the piezoelectric elements 32a, 32b and the piezoelectric element 32c. By a signal from the oscillation circuit, the vibrating body 31 bends and vibrates in the direction perpendicular to the face on which the piezoelectric element 32c is formed. In this situation, when a rotation is applied around the central axial direction of the vibrating body 31, the vibration direction of the vibrating body 31 changes by a Corioli's force, according as a change of the vibration direction, a difference is generated between output voltages of the piezoelectric elements 32a and 32b. Thus, a rotational angular velocity applied to the vibrating gyroscope 30 can be detected by measuring the difference of the output voltages.
In the vibrating gyroscope 30 constructed as described above, supporting members 33a and 33b made of metal wire are mounted on ridge-line portions in the vicinity of the nodal points of the vibrating body 31. Both ends of the supporting members 33a and 33b are secured to the rectangular-shaped supporting bodies 35a and 35b made of metal material respectively in order to suppress the propagation and interference of the vibration of the vibrating body 31. In this arrangement, two holes 36, 36 are provided on each of the supporting bodies 35a and 35b, respectively. Both the ends of one supporting members 33a are inserted into the two holes 36, 36 on the supporting body 35a and soldered. In the same way, both the ends of the other supporting member 33b are inserted into the two holes 36, 36 on the other supporting body 35b and soldered. The supporting bodies 35a and 35b are secured to a surface of a strip-shaped board 40 made of a metal material via a cushion material 37.
However, the supporting members 33a and 33b must be secured to the two independent supporting bodies 35a and 35b, and these supporting bodies 35a and 35b must be secured to the board 40 via the cushion material 37 in the conventional vibrating gyroscope 30; therefore its structure is complicated and difficult to assemble, accompanied by rigorous dimensional accuracy.
When these members are deformed by aging and temperature variations, the deformations of each member are accumulated, which may drastically change the vibration attitude of the vibrating body 31. Furthermore, the supporting bodies 35a and 35b are small in mechanical dimensions and the motions of the supporting members 33a and 33b connected by the vibration of the vibrating body 31 cannot be suppressed sufficiently. Consequently, it is difficult that a stable vibration can be realized in the vibrating body 31, and a good characteristics can be attained from the standpoint of a sensitivity.